The number of culturable nitrifying and denitrification bacteria, ammonifiers bacteria and azotobacteria in a sample was determined by counting colony forming units (CFU).
At the early and late rice main growth stages, the numbers of soil ammonifiers bacteria decreased as follows: MF>RF>LOM>HOM>CK.
In the present study, the results indicated that different fertilization managements were significantly affected some physiological function soil microbial quantity, including the soil nitrifying and denitrification, ammonifiers, cellulose-decomposing and azotobacteria bacteria.
Meanwhile, the communities and activities of soil physiological function bacterial (nitrifying and denitrification, ammonifiers, cellulose-decomposing and azotobacteria bacteria) were affected by the soil physicochemical properties [7,8], fertilizer regimes [9, 34], type of crops and planting systems , and the fertilizer managements is an important factor for affect the communities of soil bacterial.
At the early and late rice main growth stages, the numbers of soil nitrifying and denitrification bacteria higher in HOM treatment, and the numbers of soil ammonifiers bacteria higher in MF treatment, the numbers of soil cellulose-decomposing bacteria higher in LOM treatment, the numbers of soil azotobacteria bacteria higher in RF treatment, respectively.
Effects of long-term fertilization treatments on the amount of ammonifiers bacteria, azotobacteria and cellulose-decomposing bacteria in soil at early and late rice main growth stages Items Treatment SS Ammonifiers MF 65.
4] No change Organic Carbon No change C/N ratio + - Organic matter No change pH No change Total Carbon -- Extractable P -- Microbiological Soil respiration - + Ammonifiers
No change Cellulolytics No change N fixers No change Nitrifiers No change Soil Properties Subantarctic Forest Disturbed Undisturbed Physical Hardness - + Moisture No change Temperature No change Texture Silt -- Clay -- Sand -- Chemical Total Nitrogen No change Mineral Nitrogen No change Nitrate + Nitrite -- N[H.
Data obtained from the studies show that the population of ammonifiers varies considerably for different experimental plots and depends on the quality of incoming plant residues of the previous crop (Figure 1).
6] cells/g); in peas and oats mixture, the population of ammonifiers increases (25.
The changes in the population of microorganisms that use mineral forms of nitrogen (KAA medium) containing overwhelming population of nitrifiers are similar to ammonifiers, with the only difference that their population is somewhat more than that for the ammonifiers.
According to the obtained data, the population of ammonifiers differs depending on the previous crop: for maize and silage, it varies from 12.
In the course of their decomposition and transformation into the accessible forms, an active role is played by groups of microorganisms, such as the ammonifiers, cellulose-decomposing microorganisms, and microorganisms, that use mineral nitrogen for their nutrition.